Circulating tool



Feb. 24, 1970 J. w. HARRINGTON C IRCULAT ING TOOL Filed Jan. 15, 1969dme-U W Har/fag fon INVENTOR- BY Mami/nf, l m ,fw

Afro/PMS VJ United States Patent Gf'fce 3,497,009 Patented Feb. 24, 1979U.S. Cl. 166--226 3 Claims ABSTRACT F THE DISCLOSURE The tool includestwo telescoping tubular members for installation in a pipe string. Thetwo members are connected together by screw threads so that relativerotation of the members will move one of the members axially of theother. One member is provided with lateral openings through which thefluid in the well bore can flow into and out of the tool and the pipestring, when the tool is in its open position. The other member closesoff the lateral openings, when the tool is in its closed position. Thetool is opened by unscrewing the two members. Engaging annular shoulderson the two members limit the distance the members can telescope. One ofthe shoulders is grooved to reduce the frictional force between theshoulders when the tool is closed and the shoulders are in engagement toreduce the torque required to open the tool.

This is a continuation-in-part of patent application Ser. No. 585,006,filed Oct. 7, 1966, entitled Pipe String Fill- Up Tool, now abandoned,and patent application Ser. No. 653,292, filed June 22, 1967, entitledPipe String FillJUp Tool.

This invention relates to circulating tool apparatus for use in a wellbore in conjunction with a tubular string disposed therein.

While performing operations in a well bore, it is desirable to have avalve in the pipe string that can be opened to permit fluid to becirculated between the interior of the pipe string and the exteriorthereof and which then can be closed when such circulation is notdesired. For example, during fishing operations, when an overshot orspear of the pack olf type is employed, it is often impossible toestablish circulation through the fish after the spear or overshot hasengaged the fish. Fishing operations can continue without circulationfor a while, but there comes a time, particularly when fishing in anopen hole, when it is desirable, if not necessary, to circulate the wellfor a while to make sure the drilling fluid and hole remain in the bestpossible condition. Without a circulating valve above the fishing tool,the spear or overshot would have to be released from the fish in orderto circulate the hole. This is undesirable because it is never knownwhether or not the fish can be re-engaged by the fishing tool once it isreleased therefrom.

Therefore, it is an object of this invention to provide a circulatingtool for a pipe string that can be opened and closed from the surfacesimply by rotating the pipe string.

It is a further object of this invention to provide a circulating toolthat can be `subjected to large tensile stresses, when closed, as wellas stress reversals and impact forces, such as those imposed on a drillstring during fishing operations, particularly when jars are employed toimpart large impact forces on the fish.

It is a further object of this invention to provide a circulating toolthat employs a threaded connection that is made up when the tool isclosed and which is broken and partially unscrewed to open the toolwherein the connection employed is so arranged that the force requiredto break the connection is less than that required to break the otherthreaded connections in the pipe string to insure that the otherthreaded connections are not inadvertently broken and unscrewed when thecirculating tool is being opened.

These and other objects, advantages, and features of the invention willbe apparent to those skilled in the art from a consideration of thisspecification, attached drawings, and appended claims.

By way of example, but not limitation, the preferred embodiment of theinvention will now be described in connection with the attacheddrawings, in which:

FIGURE l is a view, partially in elevation and partially in verticalsection, of the preferred embodiment of the circulating tool of thisinvention in the closed position;

FIGURE 2 is a view, partly in vertical section and partly in elevation,of the circulating tool of FIGURE 1 in the open position; and

FIGURE 3 is a cross sectional view taken along line 3-3 of FIGURE 2.

The circulating tool includes two telescoping members, first member ormandrel 10 and second member or housing 11. The mandrel is adapted to beconnected to the upper portion of the pipe string (not shown). Housing11 is connected to the lower portion of the pipe string (not shown) bysub 12.

Means are provided to connect the first and second members together andfor moving the members from a first position to a second position, whenthe members are rotated relatively in one sense. In the embodimentshown, mandrel 10 is provided with externally threaded section 13.Housing 11 is provided with internally threaded section 14. Thesethreaded sections combine to provide a threaded connection between thetwo members that will move the rst member axially into the secondmember, when the members are rotated relatively in a given sense andthat will move the first member axially out of the second member whenthey are rotated relatively in the other sense. Where the drill pipe ismade up of tool joints having right-hand threads, the threadedconnection ernployed in the tool should also be right-hand.

Section 11a of the bore of the housing below threaded section 14 iscovered with a layer of hard, wear resistant material such as tungstencarbide. Preferably, the clearance between bore section 11a and tubularsection 10a of the mandrel is a minimum, compatible with the membersmoving relatively with ease. This is desirable because it adds lateralstability to the tool, which is particularly important when the tool isin the closed position and subjected to impact loading.

A plurality of lateral openings 21 extend through the wall of housing 11below bore section 11a. It is through these openings that uids can passbetween the inside and outside of the pipe strings, when the tool isopen as shown in FIGURE 2. Preferably, these opening were elongatedslots or ports as this shape seems to reduce the tendency of the portsto become plugged with solids contained in the drilling fluid. With aright-hand threaded connection between the members, relative right-handrotation between the members will cause them to telescope to the closedposition shown in FIGURE l.

In the closed position, two seals are employed to prevent the flow offluid between the inside and outside of the tool through openings orports 21. The first is seal ring 22. This is a pressure energized seallocated in annular groove 23.

To provide an accessible annular groove for seal ring 22, the lower sideof groove 23 is supplied by annular shoulder 27 on the upper end ofbushing 12a, which is connected to the upper end of sub 12 by threads26. The sub is threadedly connected to the housing by threads 24.

The other seal is formed between lower end b of the mandrel and sealring 30, mounted on .bushing 12a.

When the tool is closed, upwardly facing annular surface 34 on the upperend of the housing engages downwardly facing annular shoulder 35 on themandrel to provide a torque transmitting connection between the members.Therefore, the length of mandrel 10 below shoulder 35 and the distancebelow the upper end of housing 11 to seal ring 30 should be closely heldto the desired dimensions. The engagement of end 10b with seal 30 notonly provides additional security against leakage through the tool, butit also helps improve the lateral stability of the tool by helping toanchor the lower end of the mandrel against lateral movement relative tothe housing. The close fit between the outside surface of the lower endof the mandrel and section 11b of the bore also increases the lateralstability of the tool, when it is closed.

Means are provided for limiting the distance mandrel 10 can be withdrawnfrom housing 11. In the embodiment shown, mandrel 10 is provided withfiange 40 just above threaded section 13. Flange 40 engages downwardlyfacing shoulder 41 on the housing and limits the distance the mandrelcan be unscrewed from the housing.

Shoulder 41 is a part of bushing 44, which is removably attached to theupper end of the housing by threads 45. The upper surface of bushing 44provides shoulder 34 that engages downwardly facing shoulder 35 on themandrel and limits the distance mandrel 10 can be screwed into thehousing. The engagement of these two shoulders provides lateralstability to the upper end of the tool and as stated above provides atorque transmitting connection between the two telescoping members.

When closing the tool, the drill pipe is rotated to the right (or to theleft it left-hand threads are used) and there is no danger that one ofthe connections in the pipe string will be inadvertently disconnected.When opening the tool, however, it is necessary to rotate the pipestring to the left and this creates the danger that a threadedconnection in the tool will be disconnected. To reduce the chances ofthis occurring, the area or surface 34 is reduced by knurling. Also,preferably the metal on the two shoulders is hardened to reduce thecoefiicient of friction between the two shoulders, when they are inengagement. This will reduce the torque necessary to break theconnection between mandrel 10 and housing 11 and thereby reduce thedanger of a threaded connection in the pipe string being unscrewedinadvertently.

In the embodiment shown, shoulder 34 is knurled with radial grooves 48that leave lands 49 for engaging shoulder 35. Preferably, a removablebushing, such as bushing 34, is employed so that the bushing can 4bereplaced from time to time as required to keep a smooth hard finishedsurface on shoulder 34. To allow bushing 34 to be easily changed, it issplit into two semicircular pieces, which are held in place aroundmandrel 10 by two bolts 50, only one of which is shown. Once connectedtogether by bolts 50, the bushing can be moved down and attached to theupper end of the housing by threads 45. Set screw 52 insures that thebushing is not unscrewed from the housing, when the tool is opened.

In operation, the tool is installed in the pipe string as shown inFIGURE 1 and the pipe string is run into the hole. When it is desired tocirculate through the tool, as for example, to condition the mud in thehole, lefthand torque is applied to the pipe string causing the-threaded connection between threads 13 and 14 to move mandrel 10 andhousing 11 axially relative to each other and open ports 21 forcirculating purposes. When the circulation has been completed,right-hand rotation will close the tool returning it to position shownin FIGURE 1 and fiuid pumped down the pipe string will travel throughthe tool and into the lower portion of the pipe string.

The housing section of the tool must not rotate as fast as the mandrelfor the tool to open or close. Therefore, there must be Something belowthe tool, such as a fishing tool in engagement with a fish, that willhold the housing against rotation sufficiently to produce the desiredrotation.

From the foregoing it will be seen that this invention is one welladapted to attain all of the ends and objects hereinabove set forth,together with other advantages which are obvious and which are inherentto the apparatus and structure.

It will be understood that certain features and subcombinations are ofutility and may be employed with reference to other features andsubcombinations. This is contemplated by and is within the scope of theclaims.

As many possible embodiments may be made of the invention withoutdeparting from the scope thereof, it is to be understood that all matterherein set forth or shown in the accompanying drawings is to beinterpreted as illustrative and not in a limiting sense.

The invention having been described, what is claimed 1. A circulatingtool for connecting into a pipe string intermediate its ends comprisingfirst and second telescoping tubular members, mating male and femalestraight threads on said first and second members, respectively,connecting the members together for axial movement of the first memberinto the second member when the members are rotated relatively in onesense and for moving the first member axi-ally out of the second memberwhen the members are rotated relatively in the other sense, meanslimiting the movement of the first member out of the second member to afirst position and means limiting the movement of the first member intothe second member to a second position, one of said members having atleast one lateral opening through which liquid in a well bore can enterand leave the tooi and a pipe string in which it is connected when themembers are in t-he first position, means closing the opening when themembers are in the second position, said first and second members havingoppositcly facing annular shoulders that engage when the members are intheir second position to transmit the torque imposed on one mem- 'ber bythe pipe string to the other member, when the pipe string is rotated inthe one sense, one of said shoulders having a knurled surface providinglands to engage the other shoulder to reduce the area in contacttherewith and reduce the torque required to break the threadedconnection when the members are in their second position and it isdesired to move the members to their first posiltion to permit fluid tocirculate through the lateral openlng.

2. A circulating tool for connecting into a pipe string comprising,first and second telescoping tubular members relatively movable axiallybetween a first position and a second position, the first member havingone end for connecting to the portion of the pipe string extending abovethe fill-up tool, the second member having one end for connecting to theportion of the pipe string below the tool and an opening through whichthe liquid in the Well bore can enter the pipe string when the membersare in the first position, mating male and female threads on the firstand second members, respectively, connecting the first member to thesecond member and for moving the members axially from the first positionto the second position when the first member is rotated relative to thesecond member in one sense, and from the second position to the firstposition when the first member is rotated relative to. the second in theother sense, means for closing the opening when the members are in thesecond position to stop the flow of liquid into the' pipe string throughthe opening including a tubular unthreaded lower section of the firstmember, located below the Imale threads on the member, to move past theopening in the second member when the members move from the first to thesecond position, a seal ring located below the opening in the secondmember to engage the lower section and seal off the opening, said secondmember having a section, below the opening into which the lower end ofthe male member extends, having a diameter only slightly larger than thelower section, said first and second members further having oppositelyfacing annular shoulders above their threads that engage when themembers are in their second position and cornbine with the lower sectionof the first member and the close fitting bore of the second member inwhich it is located to provide lateral stability to the tool when in thesecond position, one of said shoulders having a knurled surface toreduce the torque required to break the threaded connection between thetwo members when the members are in the second position and theshoulders are in engagement so the valve can be returned to the firstposition as required to allow fluid to be circulated between the insideof the pipe string and the annulus outside of the pipe string.

3. A circulating tool for connecting into a pipe string intermediate itsends comprising first and second telescoping tubular members, matingmale and female straight threads on said first and second members,respectively, connecting the members together for axial movement of thefirst member into the second member when the members are rotatedrelatively in one sense and for moving the first member axially out ofthe second member when the members are rotated relatively in the othersense, means limiting the movement of the first member out of the secondmember to a first position and means limiting the movement of the firstmember into the second member to a second position, said second memberhaving at least one lateral opening through which liquid in a well borecan enter and leave the tool and a pipe string in which it is connectedwhen the members are in the first position, said opening beingpositioned below the first member when the members are in their firstposition, said first and second members having downwardly and upwardlyfacing annular shoulders, respectively, that engage when the members arein their second position to transmit the torque imposed on the firstlmember by the pipe string to the second member, when the' pipe stringis rotated in the one sense, one of said shoulders having a groovedsurface providing lands to engage the other shoulder to reduce the areain contact therewith and reduce the torque required to break thethreaded connection when the members are in their second position and itis desired to move the members to their first position to permit fiuidto circulate through the opening in the second member, said first memberfurther having a second downwardly facing annular shoulder on its lowerend, said second member having an annular sealing face located below theopening in the second member to engage the second downwardly facingannular shoulder on the lower end of the first member and provide a sealtherebetween to prevent the iiow of fluid through the opening.

References Cited UNITED STATES PATENTS 2,905,250 9/1959 Talbott 166--2262,906,493 9/1959 Whitener 175-317 2,984,451 5/1961 Conrad 166-2263,100,538 8/1963 Sanders 166237 3,130,788 4/1964 Cochran et al 166-237 IAMES A. LEPPINK, Primary Examiner

